Here are some tips related to developing/debugging a program on nixpkgs, more specifically [neovim].
I have a hybrid nix/imperative setup to maintain a robust core of features (managed in nix via home-manager) while being able to easily test/iterate new plugins (vim-plug/packer).
I would like to mention that it is possible to maintain an out-of-nixpkgs list of neovim plugins via [nixos-doc].
Debug on nix
Debugging can be tricky on nix. Programs are built in a sandbox and when compiled with debug symbols, once opening a backtrace, paths reference non-existing files such as /build/src/
Clone the repository in ‘REPO’ since we need the source code. Note: when using nix flakes, you dont have to clone the repo to reproduce the crash, nix can handle it if you replace the flake reference ./contrib by github:neovim/neovim?dir=contrib, e.g., nix run github:neovim/neovim?dir=contrib#nvim-develop
$ nix develop ./contrib#nvim-developThen reproduce yor crash. Once the process has crashed
Note: As I usually have several neovim instances running concurrently, I like to see the process ID in the title bar: set titlestring=%{getpid().':'.getcwd()}
Open your backtrace with gdb as you are used to, for instance with: coredumpctl debug
If you check out the backtrace, you get:
TODOTrying to look at the source code is not helpful (yet):
Happily, gdb can replace prefixes of path with your suggestion:
set substitute-path /build/ ~/neovimReferences: